EP0791851B1

EP0791851B1 - Watertight camera

Info

Publication number: EP0791851B1
Application number: EP97102659A
Authority: EP
Inventors: Albert Rieger; Heinz-Andreas Kellner; Michael Reibl; Andreas Schweizer; David Barclay; Steven Chapman; James G. Rydelek
Original assignee: Kodak GmbH; Eastman Kodak Co
Current assignee: Kodak GmbH; Eastman Kodak Co
Priority date: 1996-02-22
Filing date: 1997-02-19
Publication date: 2000-07-05
Anticipated expiration: 2017-02-19
Also published as: EP0791851A3; JPH103114A; EP0791851A2; US5897225A

Description

The invention relates to a photographic camera having a first and a second body shell of rigid polymer material which can be joined with said first shell and prises an opening for a taking lens and a viewfinder.
Photographic cameras are known which are sealed against external influences such as sand, moisture etc., or against water. US-PS 4 882 600, DE-OS 28 23 607, DE-0S 31 12 875 and DE-OS 42 12 845 for example disclose cameras of this type, sometimes of watertight configuration. A photographic camera which is not watertight but sealed against sand and moisture is described in DE-A1-44 14 854.
The joint resulting in the assembled condition of the camera body is here mostly sealed using separate elastic sealing elements, for example O-rings, gaiter-like rubber elements, sealing means etc. to avoid these influences.
DE-OS 31 12 875 describes a watertight camera with a seal configuration where a filler is cast as a sealing element into the joints formed between stationary outer components of the camera. The filler is in a liquid state before casting and hardens when in place.
Furthermore, DE-OS 42 12 845 describes a watertight camera having a rear wall opening and shutting on a hinge and sealed off from the camera body by a circumferential seal. A further seal used for sealing an adjuster for the viewfinder is attached to the movable rear wall of the camera and is in sealing contact with the camera body.
Configurations of this type are marked by separate individual parts that first have to be joined together, so that the manufacture of a watertight photographic camera is time, material and cost intensive.
For photographic cameras, watertightness is, for example, achieved by an all-round body. Removing the film from these cameras is very complex, since first the outer body has to be opened and the camera removed. Only then can the camera enclosure, generally of cardboard, be opened and the film removed.
It is also known that such outer bodies can be produced by so-called injection molding processes (2-k-process) as described in the publication "Kunststoffe", 84 (1994) June, No. 6. Munich, DE.
A camera which is sealed against moisture, sand and dust and can thus be handled under normal conditions, can be created using simple means. However, if such a camera is to ensure watertightness, i.e. is to allow usage under water as well, a considerable amount of time, material and money is required for the struction and manufacture.
The object underlying the invention is to create a photographic camera which can be designed and manufactured in a simple manner and is protected against external influences such as dust and moisture thus allowing normal usage and which ensures dependable watertightness thus allowing the camera to be used under water. In addition, a simple removal of film and batteries after complete exposure of a film as well as inexpensive recyclability of the used camera body is to be assured.
These objects is achieved in accordance with the invention using the features in claim 1, 9, 23 and 28.
Due to the fact that a first body shell forms the front section of the camera and a second body shell the rear section and that the two body shells comprise a covering layer of an elastic polymer material, said layer being applied using a multiple-component injection moulding process and being connected to each body shell by chain looping (molecular entanglement) of the polymer materials, and that - using a multiple-component injection molding process - a sealing means of an elastic polymer material, in particular a thermoplastic elastomer, is moulded to an edge of at least one body shell that forms the joint and at least to an edge forming an opening of the camera body and is connected to the body shell by chain looping of the polymer materials, a photographic camera can be created which is not only protected against external influences but also ensures watertightness and manages without additional and separately attached sealing elements. The adhesion of the sealing means in accordance with the invention is achieved during the injection moulding process by chain looping of the molecules between the material of the body shell and that of the sealing means. Additional adhesion connectors, such as adhesives or the like, are not necessary.
Advantageously, the sealing means is of droplet shape on the edge of the first body shell, with the second body shell having a circumferential groove in which the sealing means is deformed in the assembled state of the body shells such that the camera body is watertight. Owing to a sealing element-like configuration of the second body shell in the area of the circumferential seal, the latter is well protected against mechanical effects, such as knocks etc.
To lock and seal the viewfinder, a body opening for that purpose is provided with the thermoplastic sealing means around its edge, said means having an undercut associated with the edge of the viewfinder.
In a further advantageous modification of the invention, shutter covers are associated with the body openings provided in the area of a film cartridge chamber, battery compartment or the like and are hinge-connected on one side to a body shell by means of an appropriate film hinge.
A covering layer applied by multiple-component injection moulding on the outer surfaces of the body shells is also connected to them by chain looping. By a suitable color additive to the elastomer, a camera body that can be advantageously designed is achievable. Raised areas of the covering layer and areas free of the latter ensure in addition a good grip on the camera above and under water. A carrying means designed as a lug for attachment of a carrying strap or the like forms an integral unit with the covering layer, such that a low-cost manufacture is possible without additional fitted parts and handling of the camera under water is further improved. In addition, a good shock-absorbing effect for the camera can be achieved using the "covering layer enclosure".
In a further advantageous modification, the covering layer and the carrying means form an integral unit, i.e. they are applied to the body shells during one manufacturing process step using the multiple-component injection moulding process, thereby achieving a particularly inexpensive manufacture. The configuration of the body in accordance with the invention further prevents any inadvertent opening of the camera by the user, since the locking means provided on the body shells are concealed by the shells in the connected state.
Another advantage during manufacture of a photographic camera made of a first and a second body shell of rigid polymer material which can be joined together and have openings for a taking lens and a viewfinder consists in that at least the body shell forming the camera front section is first moulded in a tool using a rigid polymer material and that in the same tool a covering layer made of an elastic polymer material is then connected to the body shell by chain looping of the polymer materials using the two-pack injection moulding process.
Better recyclability than in the prior art, and hence also better protection of the environment, is achieved in that the body shells can be crushed without separation of the polymer materials using known devices, and the resultant material mix can be used as an admixture for the manufacture of new camera components, with the admixture to the new polystyrene material being in a ratio not exceeding 25 : 100. As a result, a greatly improved impact strength is achieved in the newly manufactured camera components when compared with polystyrene.
Further advantages of the invention can be inferred from the subclaims and are illustrated with reference to an embodiment shown in the drawing.
The drawing shows in

Fig. 1: the body in accordance with the invention in an exploded view,
Fig. 2: the camera in a further embodiment in an exploded view,
Fig. 3: the camera in a rear view,
Fig. 4: the opened camera body in a schematic sectional view in the area of the body jointt along the line I-I in Fig. 3,
Fig. 5: the watertight closed camera body in a schematic sectional view in the area of the body jointt along the line I-I in Fig. 3, and
Fig. 6: a shutter cover in a schematic sectional view along the line II-II in Fig. 3.

The photographic camera comprises a front body shell 1a and a rear body shell 1b for accommodating a frame 11, as shown in schematic form in Figs. 1 and 2. The frame 11 is of light-tight configuration, for example by suitable blackening, and is provided with a film take-up and film cartridge chamber 11a, respectively, a film supply chamber 11b, an opening 11c for the shutter etc. By means of engaging elements 6b forming an integral unit with the frame 11, the latter can be connected in light-tight manner to the rear body shell 1b, in particular by means 12. Said means are formed by webs (not illustrated) which are arranged on the frame 11 in a labyrinth-like fashion and engage with corresponding recesses in the body shell 1b. The frame 11 and the body shell 1b thus form a light-tight space for the film.
Both body shells 1a and 1b consist of a rigid polymer material, preferably a polystyrene, with the front body shell 1a being optically transparent and the rear body shell 1b being light-tight. Both body shells 1a and 1b are firmly connectable by locking means 9a and 9b. The locking means comprise the locking hooks 9a formed in one piece with the body shell 1a, and the elastically flexible locking strips 9b formed in one piece with the body shell 1b. In the assembled state of the body shells, the locking means 9a, 9b are covered by the body walls and are hence not accessible for unlocking. As shown in Fig. 1, at least one marked wall area 9d is provided for that purpose on the body shell la which can be cut through using a tool, for example a screwdriver, to unlock at least one of the engaged means 9a and 9b. This is achieved by providing in the wall areas 9d openings in the body shell 1a which are closed only by the thermoplastic covering layer 3. Furthermore, an opening 20 is provided in the body shell 1b for fitting a viewfinder 8.
As shown in Fig. 3, the body shell 1b forming the camera rear section has body openings 30 and 40 having the shutter covers 13 and 15 associated with the battery compartment and the film take-up and film cartridge chamber, respectively, and being hinge-connected to the body shell 1b by means of a film hinge 13b and 15b. To remove a film once it has been fully exposed or to remove the battery, rapid access is therefore possible by destroying the seals described in the following and arranged between the shutter covers 13 and 15 and the body shell 1b.
On the body shell 1a, a sealing means 2 of droplet shape and comprising a thermoplastic elastomer, styrene-butadiene (ISO designation: TE(PEBBS +PP)), is provided on the edge 2a forming the joint of the body, said sealing means being adapted to be pressed into a groove 4 running all round the body shell 1b. In the pressed-in and assembled state of the body shells, respectively, watertightness is already achieved by an over-dimensioning of the droplet-shaped sealing means 2 in comparison with the groove 4, without the aforementioned locking means 9a and 9b having to be connected to one another. Since the resetting forces of the sealing means act vertically to the joint, no further force is necessary to keep the body shells together in the unloaded state.
Also, the sealing means 2 is provided on an edge 20a forming the viewfinder opening 20 into which the optically transparent viewfinder can be pressed in watertight manner. For carrying the camera, a carrying means 9c designed as a lug for suspension of a carrying strap or the like is provided and forms an integral unit with the covering layer 3. The sealing means 2 is provided in its further embodiment on the outer surfaces of both body shells 1a and/or 1b as a covering layer 3. The latter has, for improvement of the grip, areas 3a that are raised. Areas 3b free of covering layer 3 further improve the grip qualities owing to the resultant differing surface heights. For expedient and aesthetic reasons a free surface 13 is provided in an area around the lens, which is not covered by the covering layer an on which a C-shaped information plate is arranged on the inside of the body. The information on said plate is readable form the exterior of the body because the body shell 1a is optically transparent. Between the lens 7 and the inner edge formed by the C-shaped plate, a non-transparent cup 14 consisting of a thermoplastic elastomer is provided which encloses the lens. The C-shaped surface 13 and the information plate are configured such that they partially enclose the non-transparent cup 14.
The body shells 1a and 1b, the sealing means 2, the covering layer 3 and 3a, and the carrying means 9c are made in a multiple-component injection moulding process, in particular a two-pack process, such that looping of the molecule chains results between the two polymer materials. In a first injection moulding step, the body shell 1a is made from polystyrene and in a second step, without a change of the mould, the styrene-butadiene sealing means 2, the covering layer 3 and 3a and the carrying means 9c designed as a lug are applied. The manufacture of the body shell 1b from polystyrene is achieved similarly, with the styrene-butadiene elastomer now not being applied to the edge 2a; instead the edges 13a, 15a of the shutter covers 13 and 15 are enclosed with the sealing means 2, as shown in Fig. 3. At the same time, the covering layer 3 and 3a and the sealing means 2 are applied to the edge 20a of the opening 20 for the viewfinder 8. This seal has an undercut to simplify pressing in of the viewfinder into the seal. In a further embodiment in accordance with the invention, the viewfinder is inserted into the tool mould before the application of the thermoplastic elastomer and connected to the body shell 1b in watertight manner using the injection moulding operation for application of the sealing means 2. The viewfinder 8 is thus aligned with the C-shaped information plate provided with a viewfinder window.
The covering layer 3 and 3a is best restricted to certain surface areas improving the grip on the camera, but can also comprise the entire outer surface with the exception of the opening for the lens 7, the viewfinder 8, the opening for the flash unit and the areas 3b. By adding suitable colorants, the body can be colored to achieve light-tightness or left transparent.
For the body shells 1a, 1b and for the sealing means 2, the covering layer 3 and the holding means 5 and 9c, polycarbonate/polyurethane can also be used in addition to the material combination already stated of polystyrene/styrene-butadiene.
An actuating means 12, comprising a thumbwheel with an integrated release button for film transport and release is connected to the body shells in watertight form. To that end, the body shell 1a has a fully cylindrical opening with a special shaped collar for accommodating a sealing element and for supporting the thumbwheel, which however is not shown in the drawing. The release button designed as a watertight rubber diaphragm release transmits in known manner the release movement by means of a plunger to a release lever arranged inside the camera (also not shown).
In a further embodiment, shown in Fig. 2, the frame 11 is connectable in light-tight manner to a rear section 11d by means of engaging elements 11e and 11f, in particular means 12. Said means are formed by webs (not illustrated) which are arranged on the frame 11 in labyrinth-like fashion and engage with corresponding recesses in the rear section 11a. The frame 11 and the rear section 11d thus form a light-tight area for the film. Accordingly the body shells 1a and 1b forming the camera front and rear sections comprise an optically transparent polystyrene or polycarbonate whose outer surfaces can be variably formed using the means already described.
After complete exposure of the film, the body 10 is opened using a tool, as already described, and both body shells are conveyed to a device known per se for crushing, for example a shredder, without separation of the materials. The resultant material granulate mixture can be used as an admixture for making new light-impermeable camera components by injection moulding, where exclusively the material combination polystyrene/styrene-butadiene is used for the body shells 1a and 1b and for the sealing means 2, the covering layer 3 and the holding means 5 and 9c.
The admixture to the new polystyrene material for injection moulding is expediently a maximum of 25% of the new material.
It is within the framework of the invention that the photographic camera can also be created without openings 30 and 40 for the shutter covers 13 and 15.

Claims

A watertight camera having a film transport device (12), a lens (7), a flash unit, a viewfinder (8), said camera comprising:

a first and a second body shell (1a, 1b) of rigid polymer material, said first body shell (1a) forming a camera front section, said second body shell (1b) forming a camera rear section, said body shells being joined together to accommodate said film transport device, lens, flash unit and viewfinder, at least one said body shells having an edge disposed to define a joint between said body shells; and

a seal (2) of elastic polymer material on said edge (2a), characterized in that:

said seal is connected to said edge by molecular entanglement of said rigid and elastic polymer materials.
A watertight camera according to claim 1, characterized in that:

said seal (2) has an undeformed cross-section that is droplet shaped; and

said second body shell (1b) has a circumferential groove (4), said groove being underdimensioned relative to said seal such that said seal is deformed when said body shells are joined together, whereby said body is watertight.
A watertight camera according to claim 1, further characterized in that

one of said body shells has a body opening (20) for receiving said viewfinder (8), and

said seal (2) has an undercut associated with an edge (20a) of said viewfinder (18) for a locking and sealing accommodation of said viewfinder.
A watertight camera according to claim 1, characterized in that one of said body shells has body openings (30, 40), and shutter covers (13, 15) are associated with said body openings, said shutter covers being hinge-connected on one side to the body shell by a film hinge (13b, 15b).
A watertight camera according to claim 4, characterized in that said camera has a film cartridge chamber (11a) and a battery compartment provided in the area of said openings.
A watertight camera according to claim 1, further comprising

a cover (3) comprising elastic polymer material on surface areas of said body shells (1a, 1b) and connected to said body shells by molecular entanglement of said rigid and elastic polymer materials.
A watertight camera according to claim 6, characterized in that

said body shells define a surface when joined together; and

said cover (3) is provided on substantially the entire surface of said body shells exclusive of areas (3b) free of covering for gripping the body.
A watertight camera according to claim 6, characterized in that

said body shells define a surface when joined together;

said first body shell (1a) is transparent;

said body further comprises a C-shaped information plate (13) adjoining said first body shell; and

said cover (3) is provided on substantially the entire surface of said body shells exclusive of an opening over said information plate.
A watertight camera according to claim 6, further comprising a carrying means (9c) for holding the camera formed in one piece with said cover.
A watertight camera according to claim 9, characterized in that said seal (2), cover (3) and carrying means (9c) comprise a thermoplastic elastomer.
A watertight camera according to claim 10, characterized in that said thermoplastic elastomer is a styrene-butadiene or polyurethane.
A watertight camera according to claim 10, characterized in that said body shells and said seal, cover and carrying means are formed from polystyrene and styrene-butadiene, respectively, or from polycarbonate and polyurethane, respectively.
A watertight camera according to claim 1, characterized in that said first body shell (1a) comprises an optically transparent polystyrene or polycarbonate, and said second body shell (1b) comprises light-tight polystyrene or polycarbonate.
A watertight camera according to claim 1, characterized in that said camera includes a light-tight frame (11, 11a) having a film supply (11b) and a film winding compartment (11a), and a shutter; said lens being joined to said frame, said frame and at least one of said body shells having engaging elements (6a, 6b) connecting said frame to said body shell.
A watertight camera according to claim 14, characterized in that said engaging elements (6a, 6b) connect said frame to said body shell in light-tight relation.
A watertight camera according to claim 1, characterized in that said body shells include an integral lock (9b), said lock being covered by said body shells when said body shells are joined together.
A watertight camera according to claim 16, characterized in that said first body shell (1a) has marked wall areas (9d) that can be cut through using a tool to unlock at least one of said locks.